1. Field of the Invention
The invention relates to the production of 1,3-cyclopentanedione.
2. Background of the Art
1,3-Cyclopentanedione or its derivatives are interesting intermediate products for numerous active ingredient syntheses, e.g., according to Chemical Abstracts, 107:197620 it is useful as the starting product for the production of a prostaglandin intermediate product or according to Tetrahedron Letters, Vol. 22, No. 44, (1981), p. 4385ff, as base substances for the antibiotic Kjellmanianone. Other uses are listed in Aldrichimica Acta, Vol. 10, No. 1, (1977), p. 19.
The known processes for the production of 1,3-cyclopentanedione are just as numerous.
According to widespread synthesis methods, 1,3-cyclopentadiene is used as the starting product, which is converted into 1,3-cyclopentenediol, by oxidation into 1,3-cyclopentenedione and, after final hydrogenation, into 1,3-cyclopentanedione. As described by Lick et al. in Chem. Ber., 111, (1978), p. 2466, these methods are connected with numerous difficulties and are not very successful in the production of considerable amounts of product. The same authors have developed a process of their own in which 2-norbornene is converted into 1,3-cyclopentanedione in a three-step synthesis with a 70 percent yield [Chem. Ber., 111, (1978), p. 2461f].
By the necessary ozonolysis at -60.degree. to -70.degree. C., required twice in the process, the process because of the energy expenditure (cooling, ozone production) is not very profitable for conversion into an industrial process.